Various known tire sealants contain ethylene glycol as an antifreeze agent. Antifreeze agents are needed in order for the sealants to be effective at cold winter temperatures, sometimes approaching −30° C. or lower. However, ethylene glycol is toxic to the environment.
Various improved tire sealants use other organic antifreeze agents that are environmentally safer than ethylene glycol. U.S. Pat. Nos. 7,388,041 and 7,868,061, both to Cegelski et al., disclose a puncture sealing composition that includes at least a rubber latex and an antifreeze agent. The antifreeze agent can be glycerin, potassium acetate, or a solution of glycerin and potassium acetate, suitably mixed with water. U.S. Pat. No. 8,772,370, issued to Sulemanji, discloses a puncture sealing composition that includes at least a rubber latex and an aqueous antifreeze solution. The aqueous antifreeze solution includes an antifreeze agent selected from the group consisting of trimethyl glycerine, dimethyl sulfoxide, and combinations thereof.
U.S. Patent Application Publication 2011/0257282 to Alexander describes an effort to combine aqueous tire sealants with an aerosol propellant to facilitate injection and uniform dispensing of the tire sealant. This technology is deemed useful for injecting tire sealant into tires at locations remote from service stations. For instance, if a tire is flat, a pressurized container filled with sufficient quantities of aerosol propellant/tire sealant to inflate the tire at ambient temperature, to yield a tire pressure that is sufficient to support the weight of the vehicle and drive to a tire repair facility.
When aerosol injection is used, the ingredients of the tire sealant should be uniformly dispersed to facilitate uniform dispensing of the tire sealant. For instance, poor mixing of the propellant/inflator with the remaining ingredients of the tire sealant can result in incomplete or ineffective dispensing of the sealing composition. Additionally, the tire sealant must be injected under sufficient pressure to overcome the resistance of the valve, sometimes called the “maximum injection pressure” needed to open the valve and initiate the injection. Once the valve is opened, the tire sealant can flow into the tire at a lower pressure, sometimes called the “drop injection pressure.”
There is a need or desire for an aerosol tire sealant that overcomes the resistance of the valve more easily, enabling greater efficiency in inflating the tire using a pressurized aerosol sealant container.